11g extended SQL_TRACE event

Not for the first time, I’ve gone looking for more detail on this extended functionality in 11g.
And not for the first time, I’ve started off looking for dbms_monitor extended functionality and not found it and then wasted time trying to remember what I’m looking for:

Note to self – what I’m looking for is not dbms_monitor but simply:

alter session|system set events 'sql_trace[SQL:<sql_id>]...';

For further details, see:
http://oraclue.com/2009/03/24/oracle-event-sql_trace-in-11g/
http://tech.e2sn.com/oracle/troubleshooting/oradebug-doc